Armchair



FIG. 1 is a front perspective view of an armchair showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right elevation view thereof; and,

FIG. 6 is a top plan view thereof. 

CLAIM The ornamental design for an armchair, as shown and described. 